Stateful, Double-Buffered Dynamic Navigation Voice Prompting

ABSTRACT

A navigation system written in J2ME MIDP for a client device includes a plurality of media players each respectively comprising a buffer. A navigation program manages the state of the plurality of media players. The plurality of media players are in either one of an acquiring resources state, and a playing and de-allocating state. The use of a plurality of media players each respectively comprising a buffer overcomes the prior art in which navigation system can cut off a voice prompt because of the time-consuming tasks associated with playing a voice prompt.

The present invention claims priority from U.S. Provisional ApplicationNo. 60/996,373, entitled “Stateful, Double-Buffered Dynamic VoicePrompting For J2ME(MIDP) Personal Navigation on a Personal ElectronicDevice” to Eric Wistrand, filed on Nov. 14, 2007, the entirety of whichis expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to wireless telecommunication. Moreparticularly, it relates to wireless carrier location based services(LBS) and J2ME wireless client LBS related software and apparatus.

2. Background of the Related Art

Existing voice navigation systems typically use standard reusable voiceprompts preloaded on client devices. These standard voice prompts areusually carefully crafted to be reusable in all situations. Allsituations match to a pre-loaded or concatenated voice prompt. However,the present inventor has appreciated that such existing navigationsystems severely limit product usability and quality due to a compromisein prompt length, scope and quality in order to achieve the timingrequirements.

Voice navigation systems written in Java Platform Micro Edition (J2ME)often produce late and missed voice prompts. This sometimes results inthe absence of a street name in a voice prompt, e.g., just speaking“Turn Right in 500 feet”. The indicated pre-storage voice fragment filesare concatenated at the time they are needed. Even the number ispre-stored and concatenated. This results in a situation where the voiceprompt is not dynamic and does not have the street names andpoint-of-interest (POI) name.

Voice prompts in a J2ME navigation system are typically dynamicallycreated (based on the client navigation, the location of the deviceduring navigation) on a voice server and retrieved according to theproduct requirements. An exemplary product is the TCS Navigator productcommercially available from TeleCommunication Systems, Inc.headquartered in Annapolis, Maryland. This first part, the promptcreation, is performed some time before the actual situation occurs inanticipation of the impending situation requiring a voice prompt. Thevoice prompt is cached on the client device (phone) for use in the verynear future (usually a matter of seconds). This caching process isrelated to the present invention in that the invention solves a problemoccurring upon use of a cached voice prompt.

FIG. 3 illustrates a conventional system for playing navigation voiceprompts. In particular, the conventional system for playing navigationvoice prompts includes hardware resources 140, asynchronous hardwareinterface, a media player 10, and a local storage 120. During startup,media player 10 reserves a portion of local storage as a buffer 11. Aclient navigation program 160 manages the media player 10.

In particular, the problem solved by the present invention comes in thestage when the navigation program 160 must play the voice prompt in atimely manner. Dynamic, location-based voice prompt files are passedfrom local storage 120 (via a pointer) to the asynchronous hardwareinterface 130 which must then acquire scarce or exclusive hardwareresources 140 to allow the media player 10 to play the voice promptfile. The media player 10 needs to perform a number of time-consumingtasks before it is ready to be started, after receiving the voice promptfile. Additionally, these acquisition tasks must occur sequentially andthe various states of the media player 10 must be managed by the clientnavigation program 160. After playing the voice prompt, the system'smedia player 10 must then release fully and completely these “scarce orexclusive hardware resources”, hardware resources 140, related to thespecific voice prompt. This is because the exclusive hardware resources140 can only be acquired after the handle to a specific voice prompt hasbeen successfully passed into the media player's 10 interface. As aresult, a client navigation program 160 may not acquire and hold theseexclusive hardware resources 140 and simply replace the voice promptcontained within the hardware resources 140.

As a result, timing is very important in navigation systems, not onlyfor product quality but also for the safety of those using a navigationproduct. Therefore a client navigation program 160 must play timely andaccurate voice prompts.

SUMMARY OF THE INVENTION

In accordance with the principles of the present invention, a navigationsystem for a client device includes a plurality of media players eachrespectively comprising a buffer and being in either one of an acquiringresources state, and a voice prompt and de-allocating state. Anavigation program manages the states of the plurality of media players.

In accordance with another aspect of the invention, a method ofproviding a plurality of buffers for a navigation system comprisesinstantiating a plurality of media players for a client device, each ofthe media players respectively comprising a buffer. The plurality ofmedia players each have an acquiring resources state, and a voice promptand de-allocating state. A navigation program is executed to manage thestates of the plurality of media players.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a navigation system employing a plurality of buffers,in accordance with the principles of the present invention.

FIG. 2 illustrates a lifecycle of events/states/steps for acquisition ofexclusive hardware resources and playing of a voice prompt, inaccordance with the principles of the present invention.

FIG. 3 illustrates a conventional system for playing navigation voiceprompts.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention combines both buffering and state transitioningwith a threaded wait-state mechanism, together with a dynamiclocation-based voice prompting navigation system 100 written in JavaPlatform Micro Edition (J2ME) Mobile Information Device Profile (MIDP)(for personal device navigation).

FIG. 1 illustrates a navigation system 100 employing a plurality ofbuffers, in accordance with the principles of the present invention.

In particular, the navigation system 100 includes hardware resources140, asynchronous hardware interface 130, a navigation program 160, aplurality of media players 10, 20 . . . n, and local storage 120. Eachmedia player 10, 20 . . . n has an associated buffer 11, 21 . . . n.

In accordance with the principles of the present invention, statefulmanagement of media player 10, 20 . . . n exclusive hardware resources140 is provided using a double buffer (or more buffers depending uponthe number of buffers employed) 11, 21 . . . n in, e.g., a J2ME (MIDP)personal navigation program 160.

Any method acting upon the media players 10, 20 . . . n will beasynchronous in fashion by MIDP definition. Notification that certainevents have started, completed or failed is satisfied through a listeneror callback interface.

Hardware resources 140 may include such hardware as is necessary for theoperation of the navigation system 100. Hardware resources 140 mayinclude a display, a graphics processor, a sound processor, a systembus, keypad interface, etc.

Asynchronous hardware interface 130 can allow media players 10, 20 . . .n to interface with hardware resources 130. Being asynchronous,asynchronous hardware interface 130 allows the various components of thenavigation system, and in particular, the media players 10, 20 . . . nto operate autonomously with relation to the hardware resources 140. Thetiming of data passing between the media players 10, 20 . . . n and thehardware resources can be managed by the asynchronous hardware interface130.

Navigation program 160 can be a J2ME (MIDP) personal navigation program,as is commonly used with compact mobile information devices such as cellphones and Personal Data Assistants (PDAs).

Media players 10, 20 . . . n of navigation program 160 are shown forsimplicity as including respective buffers 11, 21 . . . n therein.However, media players 10, 20 . . . n and buffers 11, 21 . . . n can beimplemented in local storage 120 and accessed through memory pointers.

Local storage 120 provides memory storage for execution of media players10, 20 . . . n, storage of voice prompts, storage of navigation history,storage of POI data, storage of user defined destinations, storage ofconfiguration data, etc. The local storage 120 can serve as storage forthe navigation system 100 and any other programs and data stored on aclient device.

FIG. 2 illustrates a lifecycle of events/states/steps for acquisition ofexclusive hardware resources 140 and playing of a voice prompt, inaccordance with the principles of the present invention.

In event/state/step 210, instances of media players 10, 20 . . . n arecreated in local storage 120. The media players 10, 20 . . . n arecreated by resolving a specific voice prompt. Memory space within localstorage 120 can be reserved for execution of media players 10, 20 . . .n and their respective buffers 11, 21 . . . n.

In event/state/step 220, the media players 10, 20 . . . n created instep 210 acquire needed hardware resources 140. The media players 10, 20. . . n can reserve within an operating system exclusive access to thehardware resources 140 to prevent any possible contention to hardwareresources 140. Other start-up processing can also occur that can includeallocating memory area, testing connectivity to hardware resources 140,etc.

In event/state/step 230, buffers 11, 21 . . . n can be filled with mediadata, such as a voice prompt.

In event/state/step 240, the volume of media players 10, 20 . . . n canbe set. An appropriate control word within media players 10, 20 . . . ncan be set that corresponds to an appropriate volume level to preventmedia players 10, 20 . . . n from playing a voice prompt at either a toolow of a volume or at a too high of a volume.

In event/state/step 250, one of media players 10, 20 . . . n can startplaying a voice prompt. The voice prompt can be instructional audioprovided by navigation program 160.

In event/state/step 260, the voice prompt played in event/state/step 250can be finished playing. Upon media players 10, 20 . . . n hitting anend of file designation for a voice prompt, the media players 10, 20 . .. n have an indication to finish playing the voice prompt and move on toevent/state/step 270.

In event/state/step 270, the buffers 11, 21 . . . n allocated in localstorage 120 in event/state/step 220 can be de-allocated. The memoryspace previously allocated in local storage 120 for buffers 11, 21 . . .n can be free for use again by any applications and for storage of anydata upon de-allocation.

In event/state/step 280, the memory space within local storage 120allocated in event/state/step 220 for media players 10, 20 . . . n canbe de-allocated. The memory space previously allocated in local storage120 for media players 10, 20 . . . n can be free for use by anyapplications and for storage of any data upon de-allocation.

In event/state/step 290, any open media players 10, 20 . . . n that havetheir associated resources de-allocated and buffers de-allocated can beclosed.

Two (or more) media player 10, 20 . . . n buffers 11, 21 . . . n arecreated upon navigation program 160 startup and remain throughout thenavigation session. Due to the inevitable multi-threaded situation ofvoice prompt navigation these media players 10, 20 . . . n are forced tobe in only one of two general events/states/steps during voice promptexecution. They are either in the event/state/step of acquiringresources (during events/states/steps 210 through 240) or they areplaying and de-allocating (events/states/steps 250 through 290). As soonas a media player 10, 20 . . . n has been given the start command (thecause of event/state/step 250) it switches from the acquiring hardwareresources 140 events/states/steps 210 through 240 to the playing andde-allocating hardware resources 140 events/states/steps 250 through290.

During and between events/states/steps 210 through 250, a waitingmechanism (not shown) is employed to guarantee proper transitions fromone event/state/step to the next. If the transitions are not madeproperly and in the correct order a media player 10, 20 . . . n errorevent will occur and be handled accordingly. This mechanism does noteffect other navigator program 160 processes and there execution whileit is waiting for the media player 10, 20 . . . n to react.

Either of the media players 10, 20 . . . n may be acted upon by adifferent user program thread or process during almost any of thevarious events/states/steps 210-290. The most used scenario with regardto this feature is the act of stopping a Voice Prompt while it isplaying.

The actual double-buffing, or plural-buffering if three or more mediaplayers 10, 20 . . . n are enacted, occurs when one media player, .e.g.,10, is generally in the playing and de-allocating event/state/step andthe another media player, e.g., 20, is at the same time acquiringresources. Due to the asynchronous nature of the media player 10, 20 . .. n hardware resources 140 and the nature of the navigationlocation-based voice prompts, it is evident that these media players 10,20 . . . n will be active at the same moment in differing generalizedstates during much of a navigation session, even in cases where thecalling (program) methods are not re-entrant in nature.

Benefits of the invention include dynamic voice prompting in a personalnavigation program 160, such as streets and POI names. It also resultsin better error handling which prevents corruption and slow down ofmedia players 10, 20 . . . n. Faster voice processing results, as does abetter user experience, because it dynamically gives you voice prompt‘according to your current surroundings’.

The invention has applicability with any company creating a navigationprogram 160 on a personal device written in J2ME for the MIDP. It alsohas applicability in a J2ME personal navigation device with dynamicvoice prompting, dynamic meaning in this instance not pre-stored inmemory when the application is loaded onto the navigation device.

While the invention has been described with reference to the exemplaryembodiments thereof, those skilled in the art will be able to makevarious modifications to the described embodiments of the inventionwithout departing from the true spirit and scope of the invention.

1. A navigation system for a client device, comprising: a plurality of media players each respectively comprising a buffer, and each having an acquiring resources state, and a voice prompt and de-allocating state; and a navigation program to manage said acquiring resources state and said voice prompt and de-allocating state in each of said plurality of media players. 2-16. (canceled) 